Not that I really want to encourage such a "stringly typed" practice, but
it wouldn't really be that much of a stretch.
* Use haskell-src-exts[0] and haskell-src-meta[1] to make a quasiquoter
that can parse Haskell syntax
* Use syb[2] or some other generics to find VarE and ConE expressions. In
order to use SYB with TH, you'll want th-orphans[3]
* Use 'reify'[4] on the name of the variable or constructor, to see if it
exists. If it doesn't[5], replace it with (LitE (StringL (nameBase name)))
Shouldn't really be much code at all! :D
-Michael
[0] http://hackage.haskell.org/package/haskell-src-exts
[1] http://hackage.haskell.org/package/haskell-src-meta
[2] http://hackage.haskell.org/package/syb
[3] http://hackage.haskell.org/package/th-orphans
[4]
http://hackage.haskell.org/packages/archive/template-haskell/latest/doc/html...
[5] http://byorgey.wordpress.com/2011/08/16/idempotent-template-haskell/
On Sat, Aug 31, 2013 at 11:41 PM, Mateusz Kowalczyk wrote: On 01/09/13 07:02, yi lu wrote: I want to know if it is possible that I use strings without "". If I type
*Prelude>foo bar*
which actually I mean
*Prelude>foo "bar"*
However I don't want to type ""s. I have noticed if *bar* is predefined or it is a number, it can be used
as
arguments. But can other strings be used this way? Like in bash, we can
use
*ping 127.0.0.1* where *127.0.0.1* is an argument. If not, can *foo* be defined as a function so that it recognize arguments
like *bar* as *"bar"*? Thanks,
Yi Lu You can't do this non-trivially. I think your only bet would be Template
Haskell using the second approach and even then, it's a huge, huge
stretch. I highly recommend against such ideas though. Do you really
want anything that's not bound to be treated as a String? (The answer is
‘no’). I suggest that you get used to ‘"’s. If you have deep hatred for ‘"’, you could resort to spelling out the
strings like ['f', 'o', 'o'] or even 'f':'o':'o':[]. It's a bit like asking whether you can do addition everywhere by just
typing the numbers to each other (no cheating and defining number
literals as functions ;) ). --
Mateusz K. _______________________________________________
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